What are 2 chemical properties of titanium?

How many moles of lead are in 1.50 x 10^12 atoms of lead? could you explain the answer as well and not just give it to me i am refreshing for finals and i need to know how to do it

Why is it important for scientists to review and repeat the work of other scientists? 1.a scientific theory must be tested three times before it is proven. 2.the scientific method only applies to repeated experiments. 3.an experiment may have had errors that the scientists didn't recognize. 4.the results of individual scientists may be influenced by bias. 5.an experiment must be performed twice before the data can be analyzed.

1.9 mol hcl and 3.9 mol naoh react according to the equation hcl + naoh −→ nacl + h2o . if the limiting reactant is hcl, calculate the amount of nacl formed.